It is well known that a wide variety of organic materials are susceptible to oxidative degradation in the presence of air or oxygen, especially when at elevated temperatures. Such organic materials include, for example, gasolines, diesel fuels, burner fuels, gas turbine and jet fuels, automatic transmission fluids, gear oils, engine lubricating oils, thermoplastic polymers, natural and synthetic rubber, and the like. Over the years, considerable efforts have been devoted to discovery and development of compounds capable of minimizing the degradation of one or more of such materials. As conditions of use and exposure of such materials to various oxygen containing environments change over the years, the desire for new effective oxidation inhibitors (a.k.a. antioxidants) continues.
The oxidation of oils and lubricants during use serves as one example of this trend of change over the years. Although it has been long known that oils and lubricants oxidize during use leading to the formation of organic acids and other deleterious oxygenated products, the increasing complexity of modern automotive engines and various high speed machinery and their general requirements for improved performance and less frequent maintenance has resulted in a vital need for new effective oxidation inhibitors capable of functioning effectively under these changing conditions. For many lubricant applications, new antioxidants capable of functioning at elevated temperatures and also possessing antiwear properties would be a welcome contribution.
This invention addresses the foregoing problems and needs.